23-10-25, 03:21 PM
(23-10-25, 01:35 PM)Gnasher Wrote: Before you go moving everything......
Thanks Gnasher for your detailed post. Glad I checked back to the forum before I went out to the garage and started fiddling.
There's a big element of if it ain't broke don't fix it here. Bike's a 2001 with 11,000 miles on it but new to me as of a few hundred miles ago so a bit at a time I am going though all the things I think need checking supplemented by info on here such as about the gearbox sprocket nut (done). By appearance it looks to have been loved and it isn't doing anything very much wrong when I ride it to think there is much wrong. But no service history (for what it is worth on a 24 year old bike) so reasonable assumption the carbs might not be properly balanced so I tooled up and got the Carbtune. Based on its output the carbs are now balanced better than before.
I completely get the bit about the TPS being synchronised to carb 4 and that with the Carbtune I don't actually know what vacuum it is pulling unless I tool up some more for a gauge and measure it. So maybe I actually have for maladjusted carbs that are reasonably well balanced at idle!
Anyway I take your point, silly to move the TPS at this stage so I will leave it alone. No one can read exactly 5000rpm on a tachometer dial and no one knows how accuarate the tachometer is so it would be helpful to know how close to 5000rpm is good enough since there is nothing in the manual.
If my understanding of engine control systems is correct, on a carbureted engine the ECU is only using the TPS to detect large throttle openings at low rpm so that it can retard the ignition to protect from pre-ignition and hence its setting is not super critical. If it were fuel injected then a different kettle of fish entirely. It may also show my understanding is flawed and I am talking carp, won't be the first time or last.